docs: def writeGlyph(self,
              name,
              unicodes=None,
              location=None,
              masters=None,
              note=None,
              mute=False,
              ):
          """ Add a new glyph to the current instance.
              * name: the glyph name. Required.
              * unicodes: unicode values for this glyph if it needs to be different from the unicode values associated with this glyph name in the masters.
              * location: a design space location for this glyph if it needs to be different from the instance location.
              * masters: a list of masters and locations for this glyph if they need to be different from the masters specified for this instance.
              * note: a note for this glyph
              * mute: if this glyph is muted. None of the other attributes matter if this one is true.
          """
          if self.currentInstance is None:
              return
          glyphElement = ET.Element('glyph')
          if mute:
              glyphElement.attrib['mute'] = "1"
          if unicodes is not None:
              glyphElement.attrib['unicode'] = " ".join([hex(u) for u in unicodes])
          if location is not None:
              locationElement = self._makeLocationElement(location)
              glyphElement.append(locationElement)
          if name is not None:
              glyphElement.attrib['name'] = name
          if note is not None:
              noteElement = ET.Element('note')
              noteElement.text = note
              glyphElement.append(noteElement)
          if masters is not None:
              mastersElement = ET.Element("masters")
              for glyphName, masterName, location in masters:
                  masterElement = ET.Element("master")
                  if glyphName is not None:
                      masterElement.attrib['glyphname'] = glyphName
                  masterElement.attrib['source'] = masterName
                  if location is not None:
                      locationElement = self._makeLocationElement(location)
                      masterElement.append(locationElement)
                  mastersElement.append(masterElement)
              glyphElement.append(mastersElement)
          if self.currentInstance.findall('.glyphs') == []:
              glyphsElement = ET.Element('glyphs')
              self.currentInstance.append(glyphsElement)
          else:
              glyphsElement = self.currentInstance.findall('.glyphs')[0]
          glyphsElement.append(glyphElement)